My experience with leathers is that they should be very snug when new as they break in a lot. The cheaper suits with stiffer leather will especially soften up over time and with leather conditioner and warmth, until then, they can be uncomfortable because of the cheaper materials and leather tanning process. Did you notice how soft and supple the high-dollar suits are?
The arms and legs are designed to be short and tapered so they can be worn under sport boots & gloves without interference. It won't fit like a pair of jeans or a regular leather jacket. Did you try the suit on with your gloves and boots?
I have a low price two-piece suit made by a local company, it was about the same price as the BiLT suits you looked at. It's literally just leather, stiches, zippers and some good CE armour; no features or vents or gadgets, no colours or designs at all. Very basic. When I first got it, it was almost impossible for me to zip the two halves together and I found it pretty uncomfortable. As I wore it in, it became much easier. Until I got my Roadcrafter, I wore that suit every single day. It is absolutely fantastic to wear now and it feels like a second skin.
I have never owned a premium suit and I wonder if the experience is any different